STL Editor Online

Make straightforward positioning and size adjustments to an STL mesh in your browser. The editor works locally on your device and exports a binary STL.

Simple mesh transforms in your browser

StlFixTool's STL Editor focuses on practical transforms rather than sculpting or CAD feature editing. Load an STL and apply uniform scaling or separate scale values along the X, Y, and Z axes. Scaling changes the mesh's dimensions; verify the resulting measurements before using the file.

Rotate the model by positive or negative 90-degree steps around each axis, mirror it along selected axes, center it on the origin, or place it on the build plate by moving its lowest Z point to zero. Undo lets you step back from recent edits. When the model is positioned as intended, export a binary STL.

A careful editing workflow

Start by checking the imported model's orientation and dimensions. Decide whether the source dimensions are already in the units expected by your printer or downstream application. STL files often lack an explicit unit declaration, so an apparently incorrect size may come from unit interpretation rather than a geometry defect.

Make one adjustment at a time and inspect the result after each change. Uniform scale preserves proportions; per-axis scaling intentionally changes proportions. Mirroring reverses a direction and may be important for handed parts, but it does not automatically confirm that a part is correctly oriented for assembly. A 90-degree rotation changes orientation without resizing.

Centering places the geometry around the origin, which may help with applications that expect a centered model. Placing on the build plate moves the minimum Z coordinate to zero. These operations alter position, not the mesh's intended manufacturing suitability. Preview the final pose and dimensions before exporting.

Local processing and privacy

The editor runs in your browser. The selected STL is processed locally and is not uploaded to StlFixTool. This makes it useful for basic edits to files you prefer not to send to a conversion service. Browser memory and graphics capacity vary, so exceptionally large meshes may be slow or unavailable on some devices.

Because the tool acts on the local mesh, your browser needs to remain open while editing. Export the result and save it somewhere you control. StlFixTool does not retain a copy of the edited file or provide recovery if your browser session closes before export.

What the editor does not do

This is not a parametric CAD editor. It does not change individual features, rebuild surfaces, create sketches, add dimensions, or repair every mesh defect. A scale, rotation, mirror, or translation changes the existing triangle geometry as a whole. The editor also cannot determine whether your transformation matches design intent.

If the mesh contains holes, non-manifold edges, or inconsistent normals, use an appropriate mesh repair tool and validate the output. If a part needs design changes rather than basic transforms, work from the original CAD source in a suitable CAD system.

Export and validate the STL

The editor exports binary STL, a compact representation of the resulting triangles. STL generally does not store material, color, or reliable unit metadata. Reopen the exported file in your slicer or mesh application, check dimensions and orientation, and use that software's analysis before printing.

Keep the original file if you may need to reverse the edit. Although undo supports recent actions within the current editing session, it does not replace a saved backup. For safety-critical or dimensionally controlled work, verify transformations using the established engineering process for the part.

Frequently asked questions